This invention is directed to the swing weighting of clubheads of metalwood clubs, which are so designated in the golf world. These clubs have become popular alternatives to or as replacements for the conventional so-called "wood" clubs.
The "metalwood" clubs are so called because the heads are in fact formed essentially of a metal shell most commonly as a cast metal shell filled with a rigid plastic foam. One method used in the manufacture of such clubheads involves lost wax investment casting of a metal shell and the injection thereinto of a rigid foam-forming composition and allowing it to set. Such a composition may be of a rigid polyurethane foam or other foam materials such as carbon fibers, etc. Since such clubheads are often found to be too light, it has usually been found necessary to apply weights of predetermined size to such clubheads in order to properly adjust the swingweight of the clubhead to fit the player.
The term "swingweighting" refers to the application of a weight to the clubhead in order to properly match the clubhead to the flexing characteristics of the shaft, which may vary to a large extent depending on the club user and/or to the design of the club. Swingweight, as designated by the principal governing bodies in the field, namely, The Royal and Ancient Golf Club of Scotland and the U.S.G.A., identified in several categories in accordance with the physical characteristics of the shaft and whether for mens or ladies clubs. This has generally been accomplished by the use of lead tape applied at appropriate positions on the clubhead or on or near the club hosel, or by providing ports in the shell for the insertion of weights. Frequently such expedients require the redesign of the clubheads or shafts or result in an increase in shaft fracture.